Former national security adviser H.R. McMaster delivered his strongest public rebuke of President Trump since leaving office, telling MSNBC on Thursday that the president is “aiding and abetting” Putin’s attempts to undermine U.S. elections by not calling out Russian meddling. “You know, Putin gets away with, I mean, literally murder or attempted, because people don’t call him out on it,” McMaster said, possibly alluding to Russian opposition leader Alexei Navalny’s recent poisoning. “And so they are able to continue with this kind of firehose of falsehood, to sow these conspiracy theories. And we just can’t be our own worst enemies.” McMaster’s recent book, Battlegrounds, had largely avoided commenting on Trump’s role in foreign affairs.

In August, intelligence officials concluded that Russia “is using a range of measures to primarily denigrate” Joe Biden ahead of Election Day. FBI Director Christopher Wray explicitly told Congress two weeks ago that Russia was engaging in “very active efforts” to interfere in the election.